1. Field of the Invention
The present invention relates to a folding configuration for an inflatable airbag curtain. More specifically, the present invention relates to a novel inflatable airbag curtain fold and method of folding to facilitate more accurate and efficient deployment of the airbag curtain into the interior of a vehicle.
2. The Relevant Technology
Inflatable safety restraint devices, or airbags, are mandatory on most new vehicles. Airbags are typically installed as part of a system with an airbag module in the steering wheel on the driver""s side of car and in the dashboard on the passenger side of a car. In the event of an accident, a sensor within the vehicle measures abnormal deceleration and triggers the ignition of an explosive charge contained within a inflator. Expanding gases from the charge travel through conduits and fill the airbags, which immediately inflate in front of the driver and passenger to protect them from harmful impact with the interior of the car. Airbag systems have also been developed in response to the need for similar protection from lateral impacts between a passenger and the side of a vehicle""s interior. This might occur when another vehicle collides with the side of the car, or in a rollover situation where the side of car is repeatedly impacting the ground.
Side impact airbag systems are designed to prevent the head of a vehicle occupant from emerging through the window opening or from colliding with the reaction surface at the side of the vehicle. Side impact airbags have a smaller area than front impact airbags in which to deploy and must be configured to inflate efficiently and in the right direction. Side inflatable airbag curtains are typically attached to the roof rail of a car behind the head liner However, despite their enormous lifesaving potential, side airbag curtains have typically been limited to use with types of certain vehicles with particular vehicle frame configurations. In part, these limitations are a result of the space and configuration constraints for fastening the inflatable airbag curtain of an airbag system to the roof rail of the vehicle.
The size, space, and timing consideration on the side of the vehicle are different than for the front of the vehicle and the fold configurations that worked for front airbags do not work efficiently for side airbag curtains.
Many inflatable curtain fold configurations do not allow the airbag curtain to deploy into the correct position between the occupant""s head and the window, or the reaction surface if the window is down, in the most efficient manner. For example, on many of the newer, sleeker vehicles, the angle of the roof rail is flatter. Typical fold configurations used on boxier cars caused the airbag curtain to deploy inwardly at the wrong angle and consequently into the passenger, in stead of down between the passenger and the side of the vehicle.
Another problem with previously known airbag curtain fold configurations is that the fold configurations caused the curtain to fold over on itself when deploying from certain roof rails, thus increasing the time for deployment and not deploying in the proper position. Yet another problem with straight roll airbag curtain fold configurations is that they immediately expand outwardly and in an annular direction and tend to bind within the head liner or otherwise facilitate interference with interior car components adjacent the place of attachment with the roof rail.
Yet another disadvantage with previously known airbag curtain fold configurations is that they cause the curtain to deploy along an improper trajectory that causes the curtain to catch on a portion of the interior of the vehicle which causes the remaining uninflated portion to ride up or move in inchworm-like motion upward instead of deploying into the proper position. Other times, the force of deployment would shear off any knobs or components inside the car when the airbag would engage them. This could cause the additional danger of flying parts.
Additionally, many airbag folding methods require extensive use of complex tools and apparatus to fold the airbag curtain. This adds to the cost of airbag manufacturing and installation. Further, many fold configurations are quite complex with multiple folds. These airbag fold configurations increase the chance of damage during the folding process. They also contain more creases which are more susceptible to tears or punctures. Under the stringent specifications for airbag manufacturing safety, these airbag curtains are more likely to have to be scrapped due to a breach in the airbag curtain""s integrity. This also increases cost.
Accordingly, a need exists for a novel airbag curtain fold configuration and method of folding that accommodates the size, space, and timing considerations of side vehicle deployment. Additionally, a need exists for such a curtain fold configuration and method of folding which would allow the curtain to efficiently deploy along the proper trajectory into the correct position between the occupant""s head and the window, or the reaction surface if the window is down. Furthermore, a need exists for such a curtain fold configuration and method of folding which will allow unencumbered airbag curtain deployment that will not bind or interfere with the roof rail, head liner, or other interior components. Still further, a need exists for such a curtain fold configuration and method of folding that is cost effective and does not require complex folding equipment. Additionally, a need exists for a fold configuration with minimal creases or folds. Such an airbag curtain fold and configuration of folding is disclosed and claimed herein.
The apparatus of the present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available inflatable airbag curtains and curtain folding methods. Thus, it is an overall objective of the present invention to provide a fold configuration for an airbag curtain and method for folding an airbag curtain to provide accurate and efficient deployment and better overall effectiveness than was possible with prior art systems.
To achieve the foregoing and other objectives, and in accordance with the invention as embodied and broadly described herein, an airbag curtain apparatus with a novel fold configuration and method of is provided. An airbag curtain includes a first side and a second side. A first edge of the airbag curtain is folded toward the first side of the air bag to create a fold portion positioned adjacent the first side of the airbag curtain. The folding of the airbag curtain may create a crease section in the airbag curtain. The fold portion may include up to about half of the airbag curtain, but preferably includes about one sixth of the airbag curtain.
The first edge of the airbag curtain contains at least one and preferably multiple attachment tabs for attaching the airbag curtain to the interior of a vehicle. An inflation conduit may be positioned adjacent the first edge of the airbag curtain to facilitate inflation of the airbag curtain.
In one preferred embodiment, the second edge of the airbag curtain is rolled toward the fold portion to create a rolled portion opposite the fold portion on the same side of the airbag. In a presently preferred embodiment, the second edge of the airbag curtain is rolled toward the second side of the airbag curtain to create a rolled portion opposite the fold portion adjacent the second side of the airbag curtain. Accordingly, the rolled portion and the fold portion are on opposing sides of the longitudinal crease section. In this configuration, the crease acts as a fulcrum causing the rolled portion of the airbag curtain to be directed into the interior of the vehicle as the airbag curtain inflates. With the rolled portion directed inwardly, and away from the roofrail and head liner components of the vehicle, the airbag curtain can unroll in the proper trajectory. Accordingly, the airbag curtain inflates to the proper position on the side of the vehicle without catching or hanging up on other parts of the car.
The height of the rolled portion may be substantially equal to the width of the fold portion. This configuration allows for efficient packaging of the airbag curtain into the overall airbag system. The single fold in combination with a rolled portion is more efficiently folded and has fewer creases which provides decreased potential for tears or holes and increased integrity for the airbag curtain.
In one preferred embodiment, the airbag curtain may contain a tether with a first end attached adjacent a first edge of the airbag curtain. A portion of the tether may be positioned within a perimeter of the airbag curtain such that it is contained within the rolled portion of the airbag curtain after folding. A second end of the tether is positioned substantially adjacent to a side edge of the airbag curtain thereby allowing the second end to be retrievable after the curtain is packaged.
These and other objects, features, and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.